diff --git a/.github/FUNDING.yml b/.github/FUNDING.yaml
similarity index 100%
rename from .github/FUNDING.yml
rename to .github/FUNDING.yaml
diff --git a/.github/ISSUE_TEMPLATE/1-bug.yml b/.github/ISSUE_TEMPLATE/1-bug.yaml
similarity index 100%
rename from .github/ISSUE_TEMPLATE/1-bug.yml
rename to .github/ISSUE_TEMPLATE/1-bug.yaml
diff --git a/.github/ISSUE_TEMPLATE/2-feature.yml b/.github/ISSUE_TEMPLATE/2-feature.yaml
similarity index 100%
rename from .github/ISSUE_TEMPLATE/2-feature.yml
rename to .github/ISSUE_TEMPLATE/2-feature.yaml
diff --git a/.github/ISSUE_TEMPLATE/3-docs.yml b/.github/ISSUE_TEMPLATE/3-docs.yaml
similarity index 100%
rename from .github/ISSUE_TEMPLATE/3-docs.yml
rename to .github/ISSUE_TEMPLATE/3-docs.yaml
diff --git a/.github/ISSUE_TEMPLATE/config.yml b/.github/ISSUE_TEMPLATE/config.yaml
similarity index 100%
rename from .github/ISSUE_TEMPLATE/config.yml
rename to .github/ISSUE_TEMPLATE/config.yaml
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yaml
similarity index 100%
rename from .github/workflows/ci.yml
rename to .github/workflows/ci.yaml
diff --git a/.github/workflows/docker-image.yml b/.github/workflows/docker-image.yaml
similarity index 100%
rename from .github/workflows/docker-image.yml
rename to .github/workflows/docker-image.yaml
diff --git a/.github/workflows/forum.yml b/.github/workflows/forum.yaml
similarity index 100%
rename from .github/workflows/forum.yml
rename to .github/workflows/forum.yaml
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yaml
similarity index 100%
rename from .github/workflows/release.yml
rename to .github/workflows/release.yaml
diff --git a/Cargo.toml b/Cargo.toml
index 03141cbbf..a70f13a38 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ resolver = "2"
 
 [workspace.package]
 version = "0.13.1"
-rust-version = "1.83" # also change in ci.yml
+rust-version = "1.83" # also change in ci.yaml
 authors = ["The Typst Project Developers"]
 edition = "2021"
 homepage = "https://typst.app"
diff --git a/crates/typst-cli/Cargo.toml b/crates/typst-cli/Cargo.toml
index 7e9b93f93..7fc1951f1 100644
--- a/crates/typst-cli/Cargo.toml
+++ b/crates/typst-cli/Cargo.toml
@@ -83,7 +83,7 @@ vendor-openssl = ["typst-kit/vendor-openssl"]
 workspace = true
 
 # The following metadata is used by `cargo-binstall`, and should be synchronized
-# with `.github/workflows/release.yml`.
+# with `.github/workflows/release.yaml`.
 [package.metadata.binstall]
 pkg-url = "{ repo }/releases/download/v{ version }/typst-{ target }{ archive-suffix }"
 bin-dir = "typst-{ target }/typst{ binary-ext }"
diff --git a/crates/typst-cli/src/update.rs b/crates/typst-cli/src/update.rs
index ec8ca71e8..316ccf160 100644
--- a/crates/typst-cli/src/update.rs
+++ b/crates/typst-cli/src/update.rs
@@ -19,7 +19,7 @@ const TYPST_REPO: &str = "typst";
 
 /// Determine the asset to download based on the target platform.
 ///
-/// See `.github/workflows/release.yml` for the list of prebuilt assets.
+/// See `.github/workflows/release.yaml` for the list of prebuilt assets.
 macro_rules! determine_asset {
     () => {
         // For some platforms, only some targets are prebuilt in the release.
diff --git a/crates/typst-library/src/model/bibliography.rs b/crates/typst-library/src/model/bibliography.rs
index a85efc810..103799f64 100644
--- a/crates/typst-library/src/model/bibliography.rs
+++ b/crates/typst-library/src/model/bibliography.rs
@@ -90,7 +90,7 @@ use crate::World;
 /// ```
 #[elem(Locatable, Synthesize, Show, ShowSet, LocalName)]
 pub struct BibliographyElem {
-    /// One or multiple paths to or raw bytes for Hayagriva `.yml` and/or
+    /// One or multiple paths to or raw bytes for Hayagriva `.yaml` and/or
     /// BibLaTeX `.bib` files.
     ///
     /// This can be a:
@@ -385,7 +385,7 @@ fn decode_library(loaded: &Loaded) -> SourceResult<Library> {
                 .within(loaded),
             _ => bail!(
                 loaded.source.span,
-                "unknown bibliography format (must be .yml/.yaml or .bib)"
+                "unknown bibliography format (must be .yaml/.yml or .bib)"
             ),
         }
     } else {
diff --git a/docs/changelog/0.9.0.md b/docs/changelog/0.9.0.md
index 0cf3c1bd8..0a4ac8268 100644
--- a/docs/changelog/0.9.0.md
+++ b/docs/changelog/0.9.0.md
@@ -21,7 +21,7 @@ description: Changes in Typst 0.9.0
 - Added [`full`]($bibliography.full) argument to bibliography function to print
   the full bibliography even if not all works were cited
 - Bibliography entries can now contain Typst equations (wrapped in `[$..$]` just
-  like in markup), this works both for `.yml` and `.bib` bibliographies
+  like in markup), this works both for `.yaml` and `.bib` bibliographies
 - The hayagriva YAML format was improved. See its
   [changelog](https://github.com/typst/hayagriva/blob/main/CHANGELOG.md) for
   more details. **(Breaking change)**
diff --git a/docs/reference/groups.yml b/docs/reference/groups.yaml
similarity index 100%
rename from docs/reference/groups.yml
rename to docs/reference/groups.yaml
diff --git a/docs/src/lib.rs b/docs/src/lib.rs
index b81f0dc66..6b3646c3f 100644
--- a/docs/src/lib.rs
+++ b/docs/src/lib.rs
@@ -35,7 +35,7 @@ macro_rules! load {
 
 static GROUPS: LazyLock<Vec<GroupData>> = LazyLock::new(|| {
     let mut groups: Vec<GroupData> =
-        yaml::from_str(load!("reference/groups.yml")).unwrap();
+        yaml::from_str(load!("reference/groups.yaml")).unwrap();
     for group in &mut groups {
         if group.filter.is_empty() {
             group.filter = group